I think lossless is worth the extra space, I freakily can hear the difference between 320 and 16/44 (its all in the cymbals for me)
but redbook, well mastered, is absolutely fantastic.
I have also heard some great 24/88 24/96 but it depends on the mastering being good in the first place.
As HD tracks won't reveal their sources many people won't bite.
My current favourite example is the Love - Forever Changes LP - on HD Tracks 24/192 it's too loud, nasty, lack dynamics
and is just headache material. On HDCD 16/44 CD that came out a few years back it sounds simply beautiful, much different masterings.